Doctor



July 9, 1935.

s; E. AKRE 2,007,418

DOCTOR.

Filed March 25, 1928 Patented July 9, 1935 rarsnr oFFics DOCTOR Saerning Eriksen Akre, Oslo, Norway, assignor, by decree of Court, to Frederik William Vickery,

London, England I Application March 23,

1928, Serial No. 264,173

In Norway March 25, 1927 9 Claims.

This invention relates to doctors for the drums of paper-making machines including calenders and the like.

Its purpose is to provide a doctor in which the blade is yieldingly supported between resilient blade while approaching each other at their free edges between which the blade is gripped. The bends in these yielding members, which bring their edges thus together while their intermediate portions are spaced apart, stiffen the members against longitudinal bending, and result in a highly uniform resistance to movements of the blade. 7

A construction of a doctor'embodying the invention is illustrated in cross section in the accompanying drawing.

Here 6 represents a rigid doctor support which may be pivoted in the usual fashion, this feature of the support forming per se no part of the invention and therefore not appearing on the drawing. Two resilient gripping members 22 and 23 are attached to the support 5 along the rear edges as by a jamming piece 1. Over an intermediate zone between the support and their free edges these members are, as shown, spaced apart by a distance considerably greater than the thickness of the blade 2. Near these free edges, however, they approach each other so that adjacent their free edges are fiat zones over substantially the whole of which they can contact with the blade when the doctor is unstressed. It will be understood that, as soon as the blade 2 is pressed upon the roll of the paper-making machine, the members 22 and 23 must yield slightly and can then have only line contact with the blade, but, due to the flattened edge zone, the distance apart of the two lines of contact under these circumstances may be determined, thus providing for any desired spring action for the blade. It is necessary that the blade should not be able to penetrate between the members 22 and 23 so as to rest upon the rigid support, and therefore its penetration into the area over which the members 22 and 23 are spaced apart is limited by suitable means such as rivets 25 extending between themembers'.

If desired, bolts 24 may be passed through the members 22 and 23 at intervals to prevent any increase in their distance apart under doctoring stresses; and these provide a means of adjusting the pressure of the members 22 and 23 upon the blade, and may take up any permanent distortion which may take place under said stresses. 5

I claim;

1. In a doctor for the drums of paper-making machines, the combination of a supporting member, a blade, and a pair of elongated resilient strips secured along one side edge upon said supporting member, said strips being spaced apart throughout their length in a part of their width to an extent greater than the thickness of said blade and each having a fiat portion contacting with said blade when unstressed over a zone adjacent to the free edge of said strips.

2.. In a doctor for the drums of paper-making machines, the combination of an elongated supporting member, a pair of elongated resilient strips secured along one edge upon said supporting member and spaced apart in an intermediate part of their width to an extent greater than the thickness of the blade, a blade inserted between the free edges of said strips, and bolts passing through the spaced portions of said resilient strips and serving to press the marginal portions of the strips adjacent to the free edges thereof against the blade.

3. A doctor for the drums of paper-making machines, comprising a rigid support, elongated resilient blade-holding means secured by one side edge to said support and having intermediate longitudinally extending portions spaced apart by more than the thickness of the blade, said means being longitudinally bent to present flat portions adjacent to the free edges adapted to receive a blade, and a blade inserted between said flat portions.

4. In a doctor for the drums of paper-making machines, the combination of a supporting member, a pair of elongated supporting strips having intermediate longitudinal zones bulging away from each other, said supporting strips being secured at one side edge upon said supporting member, and a blade inserted between the free r side edges of said strips.

5. A doctor for drums of paper-making machines or the like, comprising a rigid support member, a pair of elongated resilient strips secured along one side edge to said support member and longitudinally bent so that the intermediate portions of said strips bulge away from each other, said strips having fiat blade-receiving portions adjacent to their free side edges, a blade between said flat portions, and means preventing penetration of said blade beyond Said 55 flat portions into the space between said intermediate portions,

6. In a doctor for the drums of paper-making machines, the combination of a supporting. member, 21. pair of elongated resilient strips extending parallel to the drum, said strips being secured along one edge to said supporting member and with their median areas substantially spaced from each other, said strips having flat portions along their free edges, stop elements between said strips spaced rearwardly from said free edges, and a resilient blade frictionally held between said flat portions.

7. In a doctor for the drums of a paper-making machine, a supporting member, a flexible scraper blade, a plurality of flexible members secured to said support and directly engaging both sides of said blade.

8. In a doctor for the drums of a paper-making machine, a supporting member, a flexible scraper blade, and a pair of resilient strips secured along one edge upon said supporting member and spaced apart in part of their width 2. distance greater than the thickness of said blade, said strips having blade-engaging zones along their other edge.

9. In a doctor for the drums of a. paper-making machine, a supporting member, an elongated flexible blade having a side edge adapted to engage and scrape a drum, elongated clamping means of resilient material in clamping engagement with the blade along one side edge of said means and secured to said support along the other side edge, said means being shaped to increase substantially the longitudinal stiffness thereof.

SZEMING ERIKSEN AKRE. 

